Zur wachstumsfördernden Wirkung von Avotan bei Mastschweinen1

A note on the influence of Avoparcin on apparent digestibility and nitrogen retention in growing pigs

A metabolism trial was carried out to examine the influence of an antibiotic food additive (Avoparcin) on the apparent digestibility of nutrients and nitrogen retention in the growing pig. Two groups of pigs, comprising 12 castrates per group, were fed a barley-based diet (190g crude protein per kg dry matter) with or without the inclusion of the antibiotic (at a dietary concentration of 20 mg/kg). Addition of Avoparcin had no significant effect on the apparent digestibility of dry matter or gross energy but resulted in a small increase in the apparent digestibility of nitrogen (0·012; P < 0·05). There was a corresponding improvement in nitrogen retention (0·051) but the difference was not statistically significant.

[Nutritional-physiological effects of dietary fats in rations for growing pigs. 4. Effects of sunflower oil and coconut oil on protein and fat retention, fatty acid pattern of back fat and blood parameters in piglets]

Rations containing 12% sunflower oil (Ration II) and 12% coconut fat (Ration III) were compared with a control ration (Ration I) in a 34 day experiment with growing boars of the German Landrace breed (12-30 kg body weight). The relationships between DP and ME were held constant for all 3 rations, and because of the higher ME contents of the two fat rations, this was achieved by reducing the feed intake, relative to that of the control ration. Parameters measured were growth, composition at slaughter, the apparent digestibility of the crude nutrients and energy, the N-balance and the concentrations of urea, insulin, glucose, triglyceride and cholesterol in the blood. In comparison to Ration I, the apparent digestibilities of crude protein in Rations II and III were 5 and 4% (p less than 0,05) higher, respectively. There was little difference in the apparent digestibility of crude fat between the Rations II and III. However, large differences in the values were determined depending upon method of extraction. There were little differences in the productive performance of the animals fed the fat diets. The control animals had, however, a 13% lower growth rate (p less than 0,05) when compared at similar ME-intakes. As the energy concentration and the growth rate were higher in groups II and III, the feed conversion efficiency and the ME required per kg growth were approximately 30 and 13% lower than that of the control animals. The efficiency of protein utilization of the animals in group III was 4% higher (p greater than 0.05) and the blood urea concentration 20% lower (p less than 0.05) than that in group II. The values for the control animals were intermediate. A similar result was obtained concerning the fat content of the animals. The fat content of the animals in group III was 15.9% and this was significantly lower (p less than 0.001) than that of 21.1% measured in group II. That of the control animals, 18.6%, was not significantly different from the above values. The differences in feeding over the relatively short period of 34 days lead to marked differences in the fatty acid pattern of the backfat. The contents of myristic acid and linoleic acid were significantly different between group II and III; for the former values of 0.8% and 16.9% were determined, respectively, with corresponding values of 48.7 and 11.3% for the latter.(ABSTRACT TRUNCATED AT 400 WORDS)

[Nutritive physiological effect of dietary fats in growing swine rations. 3. Effect of sunflower and coconut kernels on protein and fat retention, backfat fatty acid pattern and various blood parameters in piglets]

Two groups, each of 9 castrated male piglets of the German Landrace breed, body weight 13-29 kg, were fed ad libitum for a 5 week period in order to determine the influence of the fatty acid composition of the dietary fat on protein and fat retention. The concentrations of urea, insulin, glucose, free glycerol and triglycerides were also determined. That fat in ration I (derived from 27% sunflower seed) contained 50% linoleic acid while that of ration II (derived from 12,5% coconut kernels) had a maximum lauric acid content of 41,8%. The relationship between digestible crude protein and ME-content was calculated to be similar in both rations. In addition protein quality was calculated to be similar in both rations. Protein deposition was determined from both nitrogen and comparative slaughter procedures. The results can be summarized as follows: The animals fed ration I had a higher daily ME-intake and growth rate than those fed ration II, although no great difference was observed in ME required per kg body weight gain. The efficiency of protein utilization was significantly better in group I and this was associated with a lower blood urea concentration. The concentrations of insulin and glucose in the blood, measured before as well as 20, 45, 60 and 120 minutes following feeding, showed little differences between the groups. The triglyceride concentration measured before and 1 and 5 hours following feeding was significantly higher (p less than 0,01) in group II. There was no significant difference in the protein and fat content of the body as well as in the daily protein and fat deposition. The fatty acid composition of the back fat was significantly influenced by the fatty acid pattern of the dietary fat. In group I the linoleic acid content was 3,6 times higher and the lauric- and myristic acid content 11,7 times lower compared to that of group II.

[Nutritive physiological effect of dietary fats in rations for growing swine. 2. Effect of an isocaloric exchange of carbohydrate energy versus fat energy in piglets on growth and various metabolic parameters in the subsequent fattening period]

The influence of different feeding regimes of piglets on fattening performance and blood composition of the subsequent fattening period (30-100 kg) was examined. Three groups of pigs fed on an isocaloric and isonitrogenous basis with rations containing either 5% fat (groups I), 18% fat (group II) or 35% fat (group III) until body weight of 30 kg, were fed ad libitum one diet from 30 kg onwards. At a body weight of 45 and 93 kg the blood concentrations of insulin, glucose, urea, free fatty acids, neutral lipids and cholesterol in response to feeding and of insulin and glucose in response to an oral glucose load was determined in pigs provided with a permanent jugular vein catheter. Moreover, the in-vitro fat synthesis from glucose was measured. At the end of the experiment the body composition was determined by chemical analysis of the carcass. Neither feed intake, daily body weight gain nor feed conversion differed significantly among the groups. Blood urea levels of the three groups did not suggest a different protein utilization. Neither feed consumption nor oral intake of glucose affected the insulin and glucose response of the three groups differently. The concentrations of free fatty acids, neutral lipids and cholesterol did not differ clearly among the groups although occasionally significance of difference was observed. In group I the in-vitro synthesis of fat was increased (p less than 0.05) at a body weight of 45 kg and appeared to be higher at a body weight of 93 kg as compared to the high fat group (group III). No clear differences between the groups were observed in the chemical composition of the carcasses. It is concluded, that isocaloric replacement of carbohydrates by fat in the diet of piglets does not affect protein and fat retention in the subsequent fattening period.